Metamaterials are rationally designed composites, the effective properties of which can go quantitatively and qualitatively beyond (= “meta”) those of their ingredients. Metamaterials with negative refractive indices and optical invisibility cloaking have been striking early demonstrations. However, the field is much broader today, encompassing many areas and aspects of physics beyond just optics.

In this talk, I start by discussing the Calderon tomography problem to introduce the mathematics behind cloaking and to highlight its general relevance. I then review experiments ranging from thermodynamics (i.e., heat conduction and diffusion) to mechanics.